Semiconductor radiation detector

Claim 1

A radiation detecting apparatus for use in detecting incident radiation pulses of predetermined duration, said detector comprising: a semiconductor detector which generates electrical charge in response to incident radiation, said detector being disposed to receive at least a portion of said radiation pulses; signal processing means, AC coupled electrically to said semiconductor detector for generating an output electrical signal accurately representing said incident radiation, said signal processing means including filter means for allowing only frequency components within a predetermined range of frequencies to contribute to said output electrical signal, said range of frequencies being determined in accordance with the duration of said incident radiation pulses so that said output electrical signal is undistorted by variations in internal electrical characteristics of the semiconductor detector.

Claim 5

The apparatus of claims 1 or 2 wherein said signal processing means comprises: an electrical charge amplifier having an input electrically coupled to said detector through a capacitor, a fast differentiator circuit connected in feedback relation with said charge amplifier; and an integrator responsive to the output of said charge amplifier.

Claim 7

The apparatus of claims 1 or 2 wherein said signal processing means comprises: a charge amplifier electrically coupled to said detector through a capacitor; a differentiator responsive to the output signals of said charge amplifier; and an integrator responsive to the output of said differentiator.

Claim 8

The apparatus of claims 1 or 2 wherein said detector comprises a wafer of a material selected from the group of cadmium telluride and mercuric iodide having a cathode electrode in ohmic contact with one surface, and at least one anode contact in ohmic contact with an opposing surface of the wafer.

Claim 11

The apparatus of claims 1 or 2 further including a second semiconductor detector disposed to receive radiation passing through the first-referenced semiconductor detector.

Claim 12

The apparatus of claims 1 or 2 wherein said signal processing means for generating an output signal comprises: a charge sensitive first stage having a first predetermined effective RC time constant; and a second stage, cooperating with said first stage, having a second predetermined effective RC time constant; said first and second predetermined effective RC time constants being determined in accordance with the duration of said radiation pulse.

Claim 15

The apparatus of claims 1 or 2 wherein said signal processing means for generating an output signal comprises: a charge sensitive amplifier having a frequency response such that only frequencies within a predetermined band of frequencies centered about a frequency approximately equal to the inverse of the duration of said incident radiation pulses contribute to said output electrical signal.

Claim 16

The apparatus of claims 1 or 2 wherein said signal processing means for generating an output signal comprises: a charge sensitive amplifier having a frequency response such that only frequencies within a predetermined band of frequencies centered about a frequency approximately equal to the inverse of twice the duration of said incident radiation pulses contribute to said output electrical signal.

Claim 17

The apparatus of claims 1 or 2 wherein said signal processing means comprises: a charge amplifier electrically coupled to said detector through a capacitor; a differentiator responsive to the output signals of said charge amplifier; a voltage amplifier responsive to the output of said differentiator; and an integrator responsive to the voltage amplifier output.

Claim 36

An apparatus for measuring the intensity of incident radiation pulses having a predetermined duration, said apparatus comprising: a wafer of a material selected from the group consisting of CdTe and HgI2 having first and second surfaces defining a predetermined thickness; a first conductive layer deposited on said first surface; a second conductive layer deposited on said second surface, said second conductive layer including a plurality of individual electrically isolated sections, each serving as a separate electrode to said wafer, whereby a plurality of individual detectors are provided on said wafer; and a plurality of signal processing means each respectively electrically coupled to a corresponding one of said separate electrodes, for detecting and processing electrical signals presented at said electrodes and for providing output signals accurately representing the intensity of radiation incident on each detector.

Claim 37

An apparatus for measuring the intensity of incident radiation pulses having a predetermined duration, said apparatus comprising: a wafer of a material selected from the group consisting of CdTe and HgI2 having first and second surfaces defining a predetermined thickness; a first conductive layer deposited on said first surface; a second conductive layer deposited on said second surface, said second conductive layer including a plurality of individual electrically isolated sections, each serving as a separate electrode to said wafer, whereby a plurality of individual detectors are provided on said wafer; and a plurality of signal processing means each respectively electrically coupled to a corresponding one of said separate electrodes, for detecting and processing electrical signals presented at said electrodes and for providing output signals accurately representing the intensity of radiation incident on each detector.

Claim 47

The apparatus of claims 38 or 39 wherein said charge sensitive amplifier and frequency filter means comprises: a charge amplifier having an input coupled to said detector through a capacitor; a fast differentiator circuit connected in feedback relation with said charge amplifier; and an integrator responsive to the output signals of said charge amplifier.

Claim 49

The apparatus of claims 38 or 39 wherein said charge sensitive amplifier and frequency filter means comprises: a charge amplifier coupled to said detector through a capacitor; a differentiator responsive to the output signals of said charge amplifier; and an integrator responsive to the output of said differentiator.

Claim 50

The apparatus of claims 38 or 39 wherein said detector means comprises a wafer of cadmium telluride having a first electrode in contact with a first surface thereof, and at least one second electrode in contact with a second surface.

Claim 54

The apparatus of claims 38 or 39 wherein said charge sensitive amplifier and frequency filter means comprises: a charge amplifier coupled to said detector through a capacitor; a differentiator responsive to the output signals of said charge amplifier; a voltage amplifier responsive to the output of said differentiator; and an integrator responsive to the output of the voltage amplifier.

Claim 55

A method for detecting incident radiation pulses of predetermined duration, comprising the steps of: disposing a semiconductor detector to receive at least a portion of said radiation, said semiconductor detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said charge; and filtering out components of said electrical output signal not in accordance with the duration of said radiation pulses so that said electrical output signal is substantially undistorted by characteristics of said semiconductor detector.

Claim 56

A method for detecting incident radiation pulses of predetermined duration, comprising the steps of: disposing a semiconductor detector to receive at least a portion of said radiation, said semiconductor detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said charge; and filtering out components of said electrical output signal not in accordance with the duration of said radiation pulses so that said electrical output signal is substantially undistorted by characteristics of said semiconductor detector.

Claim 57

An apparatus for measuring the intensity of incident radiation pulses having a predetermined duration, said apparatus comprising: a wafer of material selected from the group of CdTe and HgI2 having first and second surfaces defining a predetermined thickness; a first conductive layer deposited on said first surface; and a second conductive layer deposited on said second surface, said second conductive layer including a plurality of individual electrically isolated sections, each serving as a separate electrode to said wafer, whereby a plurality of individual detectors are provided on said wafer.

Claim 58

An apparatus for measuring the intensity of incident radiation pulses having a predetermined duration, said apparatus comprising: a wafer of material selected from the group of CdTe and HgI2 having first and second surfaces defining a predetermined thickness; a first conductive layer deposited on said first surface; and a second conductive layer deposited on said second surface, said second conductive layer including a plurality of individual electrically isolated sections, each serving as a separate electrode to said wafer, whereby a plurality of individual detectors are provided on said wafer.

Claim 65

A method for providing a measurement of radiation transmission-absorption by a cross-section of a body, comprising the steps of: generating pulses of radiation of predetermined duration; directing said radiation pulses to irradiate said body; disposing a semiconductor detector to receive at least a portion of said radiation transmitted through said body, said semiconductor detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said charge; and filtering out components of said electrical output signal not in accordance with the duration of said radiation pulses so that said electrical output signal is substantially undistorted by characteristics of said semiconductor detector.

Claim 66

A method for providing a measurement of radiation transmission-absorption by a cross-section of a body, comprising the steps of: generating pulses of radiation of predetermined duration; directing said radiation pulses to irradiate said body; disposing a semiconductor detector to receive at least a portion of said radiation transmitted through said body, said semiconductor detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said charge; and filtering out components of said electrical output signal not in accordance with the duration of said radiation pulses so that said electrical output signal is substantially undistorted by characteristics of said semiconductor detector.

Claim 67

A method for providing a measurement of radiation transmission/absorption by a cross-section of a body, comprising the steps of: generating pulses of radiation of predetermined duration; directing said radiation pulses of irradiate said body; disposing a wafer of material selected from the group of CdTe and HgI2 to receive at least a portion of said radiation transmitted through said body; disposing on one side of said wafer a plurality of spaced apart electrodes and on an opposing surface a common electrode, respective electrical charges being developed between said plurality of electrodes and said common electrode; generating respective electical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said filtering electrical output signals to provide an accurate representation of the intensity of the radiation.

Claim 68

A method for providing a measurement of radiation transmission/absorption by a cross-section of a body, comprising the steps of: generating pulses of radiation of predetermined duration; directing said radiation pulses of irradiate said body; disposing a wafer of material selected from the group of CdTe and HgI2 to receive at least a portion of said radiation transmitted through said body; disposing on one side of said wafer a plurality of spaced apart electrodes and on an opposing surface a common electrode, respective electrical charges being developed between said plurality of electrodes and said common electrode; generating respective electical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said filtering electrical output signals to provide an accurate representation of the intensity of the radiation.

Claim 69

A method for using in an apparatus for measuring relative radiation transmission/absorption of a body a radiating detector having at least one of the adverse properties of high current leakage, tailing, polarization, or memory properties, comprising the steps of: directing pulses of radiation to irradiate said body, said pulses being of predetermined duration; disposing said radiation detector to receive at least a portion of said radiation transmitted through said body, said radiation detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said electrical charge; filtering said electrical output signal to develop a filtered output signal containing only frequency components within a range of frequencies in accordance with said predetermined duration of said radiation pulse such that frequency components associated with said adverse properties of said detectors are substantially eliminated from said filtered output signal; and processing said filtered output signal to provide an accurate representation of said transmission/absorption.

Claim 70

A method for using in an apparatus for measuring relative radiation transmission/absorption of a body a radiating detector having at least one of the adverse properties of high current leakage, tailing, polarization, or memory properties, comprising the steps of: directing pulses of radiation to irradiate said body, said pulses being of predetermined duration; disposing said radiation detector to receive at least a portion of said radiation transmitted through said body, said radiation detector generating an electrical charge in response to said received radiation; generating an electrical output signal indicative of said electrical charge; filtering said electrical output signal to develop a filtered output signal containing only frequency components within a range of frequencies in accordance with said predetermined duration of said radiation pulse such that frequency components associated with said adverse properties of said detectors are substantially eliminated from said filtered output signal; and processing said filtered output signal to provide an accurate representation of said transmission/absorption.

Claim 71

A method for providing simultaneous measurements of radiation transmission/absorption in a plurality of adjacent cross-sections of a body, comprising the steps of: directing pulses of radiation to irradiate said respective cross-sections; disposing a wafer of material selected from the group of CdTe and HgI2 having disposed on one surface thereof a plurality of spaced apart electrodes and on an opposing surface a common electrode, such that each of said plurality of electrodes receives a radiation transmitted through a respective one of said cross-sections, and develops a respective electrical charge in said wafer in accordance with said received radiation; generating respective electrical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said respective filtered electrical output signals to provide respective representations of the transmission/absorption of said respective cross-sections.

Claim 72

A method for providing simultaneous measurements of radiation transmission/absorption in a plurality of adjacent cross-sections of a body, comprising the steps of: directing pulses of radiation to irradiate said respective cross-sections; disposing a wafer of material selected from the group of CdTe and HgI2 having disposed on one surface thereof a plurality of spaced apart electrodes and on an opposing surface a common electrode, such that each of said plurality of electrodes receives a radiation transmitted through a respective one of said cross-sections, and develops a respective electrical charge in said wafer in accordance with said received radiation; generating respective electrical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said respective filtered electrical output signals to provide respective representations of the transmission/absorption of said respective cross-sections.

Claim 73

A method for providing simultaneous measurements of radiation transmission/absorption of a body at a plurality of effective energy levels, comprising the steps of: directing pulses of radiation to irradiate said body, said pulses being of predetermined duration; disposing a wafer of material selected from the group of CdTe and HgI2 having a common electrode on one opposing surface, such that at least a portion of said radiation pulse transmitted through said body is incident on a surface of said wafer transverse to said one surface and said opposing surface to develop respective charges between said plural electrodes and said common electrode in accordance with the intensity of the radiation passing into the region of said wafer between respective ones of said plurality of electrodes and said common electrode; disposing on one side of said wafer a plurality of spaced apart electrodes and on an opposing surface a common electrode, respective electrical charges being developed between said plurality of electrodes and said common electrode; generating respective electrical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said respective filtered electrical output signals to provide accurate representations of said radiation transmission/absorption at the energy levels associated with said radiation passing through respective distances of CdTe.

Claim 74

A method for providing simultaneous measurements of radiation transmission/absorption of a body at a plurality of effective energy levels, comprising the steps of: directing pulses of radiation to irradiate said body, said pulses being of predetermined duration; disposing a wafer of material selected from the group of CdTe and HgI2 having a common electrode on one opposing surface, such that at least a portion of said radiation pulse transmitted through said body is incident on a surface of said wafer transverse to said one surface and said opposing surface to develop respective charges between said plural electrodes and said common electrode in accordance with the intensity of the radiation passing into the region of said wafer between respective ones of said plurality of electrodes and said common electrode; disposing on one side of said wafer a plurality of spaced apart electrodes and on an opposing surface a common electrode, respective electrical charges being developed between said plurality of electrodes and said common electrode; generating respective electrical output signals indicative of said respective electrical charges; and filtering said respective electrical output signals to develop respective filtered electrical output signals having only frequency components within a predetermined range of frequencies in accordance with the duration of said radiation pulses; and processing said respective filtered electrical output signals to provide accurate representations of said radiation transmission/absorption at the energy levels associated with said radiation passing through respective distances of CdTe.